Antistatic finishing of surfaces

ABSTRACT

Antistatic finishing of surfaces of shaped articles, especially textiles, which tend to acquire an electrostatic charge, using quaternary ammonium compounds which contain 2 to 4 hydroxyethyl groups per ammonium group.

United States Patent [191 Jorek et al.

[451 Oct. 21, 1975' ANTISTATIC FINISHING OF SURFACES Inventors: HelmutJorek; Rolf Fikentscher,

both of Ludwigshafen; Joachim Kur ze, Leutershausen, all of Germany;Herbert Helfert, Trenton,

Mich. Assignee: Bast Aktiengesellschaft,

Ludwigshafen (Rhine), Germany Filed: Mar. 1, 1974 Appl. No.: 447,228

Foreign Application Priority Data Mar. 1,1973 Germany .......2310186[56] References Cited UNITED STATES PATENTS 2,096,749 10/1937Kritchevsky 117/1395 F 2,205,042 6/1940 Lenher 61 a1 117/1395 F3,065,110 11/1962 Hagge e161. 117/1388 UA 3,174,985 3/19 5 Berger117/138.8 N 8/1972 R6111 117/1395 CQ Primary Examiner-Michael R.Lusignan Attorney, Agent, or Firm-Johnston, Keil, Thompson and Shurtleff[57] ABSTRACT Antistatic finishing of surfaces of shaped articles,especially textiles, which tend to acquire an electrostatic charge,using quaternary ammonium compounds which contain 2 to 4 hydroxyethylgroups per ammonium group.

'2-Claims, No Drawings ANTISTATIC FINISHING OF SURFACES This inventionrelates to the antistatic finishing of surfaces of shaped articles,especially textiles, which tend to acquire an electrostatic charge,using quaternary ammonium compounds which contain 2 to 4 hydroxyethylgroups per ammonium group.

It is known that many articles consisting of macromolecular materialstend to build up an objectionable electrostatic charge during processingor in use. This tendency is particularly common with articles ofsynthetic macromolecular materials; however, it is not restricted tothese but also occurs with fibers of cellulose esters and even fibers ofcellulose, regenerated cellulose, silk, wool and other vegetable andanimal products, when the moisture content of these fibers which isprimarily determined by the relative atmospheric humidity falls below acertain limit. This limit differs from one type of fiber to another.

Numerous chemical compounds have already been proposed as antistaticagents. The conventional antistaticagents are mostly longchain alkyloraralkyl compounds of the non-ionic, anionic or cationic type. Amongstthese, the cationic fatty alkyl compounds of nitrogen or phosphorus, inthe form of their tertiary or quaternary salts, are preferred because byvirtue of their substantivity and their orientability on the surface ofthe fiber they produce very good antistatic effects. The orientation ofthe molecules of these surfaceactive positively charged compounds isattributable to their chemical structure which is characterized by along hydrophobic alkyl radical of 8 to carbon atoms and a hydrophilicsalt-forming group. A cycloaliphatic or aromatic radical can take theplace of the longchain alkyl radical, but, evidently for steric reasons,these products are less effective antistatic agents than the aliphaticcompounds.

The disadvantage of these compounds is that they are strongly cationic,hence react both with anionic surfactants and with anionic dyes to formsparingly soluble salts, and therefore cannot be used conjointly withsuch surfactants or dyes.

Compounds which act as antistatic agents and, in spite of theirpronounced positive charge, do not react as cationic compounds have beendisclosed in the literature. These are substituted urea derivativeswhich, however, suffer from the disadvantage when used on textiles thatthe substrate finished with them can develop an unpleasant fishy odor onstorage under adverse conditions. I

It is an object of the present invention to provide a process forantistatic finishing, especially of textiles, which is at least as goodas the conventional processes in respect of antistatic activity but doesnot suffer from the disadvantages described.

We have found a process for antistatic finishing of surfaces of shapedarticleswhich tend to build up an electrostatic charge, by coating withammonium salts, wherein the coating agents used are ammonium salts ofthe formula Q-I ((:H. cH, oH)z x6 where X is a monovalent organic orinorganic anion or the n-th part of an n-valent anion of a water-solubleacid, (i.e., one equivalent of an anion of a water-soluble acid) R and Qindependently of one another are each hydroxyalkyl of 2 or 3 carbonatoms, alkyl of l to 6 carbon atoms or benzyl and Q can also be theradical in which A is alkylene of 2 to 6 carbon atoms. Compounds of thesaid formula in which R is hydroxyethyl and Q is methyl or ethyl arepreferred.

The compounds can be obtained conventionally-by reaction ofappropriately substituted diethanolamines or of triethanolamine withalkylating, hydroxyalkylating or benzylating agents, such as dialkylsulfates, alkyl 7 halides or alkyl dihalides, toluenesulfonic acid alkylesters, benzyl chloride or ethylene oxide or propylene oxide togetherwith acids, in equimolar ratios. The quaternization reactions take placeat temperatures of 20 to C though with some sluggish quaternizing agentstemperatures of up to C are required. Solvents can be used for examplefor the purposeof cooling the mixture through boiling of the solvent.

As the anion X it is possible to use more or less any watersolubleorganic or inorganic acid radicals. For economic reasons, the anions ofindustrially available acids, for example of sulfuric acid, hydrochloricacid, hydrobromic acid, toluenesulfonic acid and methylsulfuric acid arepreferred.

Compounds with fewer than two 2-hydroxyethyl groups on the quaternarynitrogen are not sufficiently active antistatically.

The compounds, and their manufacture, are not claimed herein.

In contrast to the quaternary ammonium compounds conventionally used forthis purpose, the compounds of the formula shown exhibit an antistaticaction, even at low relative atmospheric humidities, to a hithertounknown degree. They are therefore particularly suitable for theantistatic finishing of fibrous textile materials of all kinds, forexample fibers, filaments, tops, card slivers, yarns, non-woven fabrics,felts, woven fabrics and knitted fabrics, consisting of synthetic highmolecular materials, such as'linear polyesters, polyamides,acrylonitrile polymers, p'olyolefins and polyvinyl compounds, orconsisting of natural high molecular weight materials or theirderivatives, such as cellulose, regenerated cellulose, cellulose esters,silk, wool and other vegetable and animal materials.

The antistatic effect of the compounds persists for a prolonged periodeven at high temperatures; textile materials finished with thesecompounds do not yellow, because of the high heat stability of thecompounds. In spite of their pronounced positive charge the compounds donot behave as cationic compounds, that is to say they react neither withanionic surfactant nor with anionic dyes to form precipitates, so thatthey are universally applicable without the hazard of the difficultieswhich arise, when using the conventional cationic antistatic compounds,during subsequent finishing processes such as dyeing, wash-and wearfinishing and hydrophobic treatments. Their particular advantage is thateven on storing the finished textiles under adverse conditions a fishyodor does not develop.

In addition, these antistatic agents have further advantages in use overthe fatty alkyl-ammonium salts.

They give completely clear colorless solutions in water even at roomtemperature. The viscosity of these solutions is low even atconcentrations of 50 to 80 per cent by weight of the compounds, so thatthey can be 4 nation products of natural fats of animal or vegetableorigin, oxyalkylation products of fatty acids, sulfonate salts ofalkylated aromatics, sulfuric acid ester salts of fatty alcohols and ofpartial fatty acid esters of polyhydsprayed at high concentrations. As aresult of the ab- 5 ric alcohols, salts of partial phosphoric acidesters, and sence of long alkyl radicals, the compoundsdo notafdispersions of polyethylene and other vinyl comfeet the handle orappearance of the fibrous materials pounds, such as copolymers of butylacrylate, quatertreated therewith and do not increase the soilingtennary vinylimidazole and methylolacrylamide.

dency, in the sense of mechanical adhesion of dirt par- Apart from thetreatment of fibrous materials, the ticles to the surface of the fibers.For these reasons, the compounds of the above formula have provedoutcompounds are particularly suitable for the antistatic standinglysuccessful in the antistatic surface treatment treatment of textileswhich suffer heavy soiling from of non-fibrous articles of any materialswhich tend to dust, for example net curtains, carpets, furnishingfabbuild up an electrostatic charge, especially of materials rics andindustrial fabrics, such as dust filters, conveyor usually referred toas plastics or resins. Here again, belts and drive belts which in mostcases are not subaqueous solutions are suitable and these can again bejected to intensive wet washing. In addition, the abapplied by dippingor spraying, but can also be spread sence of a long alkyl radical andhence the absence of by rubbing the surface to be protected with animprega fatty character has the advantage that the crocking nated cloth.In this way it is possible to provide, for exfastness of dyeingsproduced with disperse dyes and aftample, films, phonograph records,lighting appliances, ertreated with the compounds of the above formulais refrigerators, radio cabinets and plastics-veneered furnot adverselyaffected even in the case of deep shades. niture'with antistatic surfaceprotection.

It is very simple to use the compounds of the above Tables 1 and 2 showthe antistatic action of the comformula for the antistatic treatment offibrous materipounds on textile material. The data are determined asals. The treatment is suitably carried out with aqueous follows:solutions which are applied to the material to be 5 g of continuousfilament of polycaprolactam (dtex treated by any desired method, forexample by dipping 67 f 12 Z) or polyethylene terephthalate (dtex 75 f24) or spraying, after which the material is dried. The appliare woundup on a winch of 120 cm circumference. cation of 0.03 to 2 per cent byweight of the com- This material is treated depending on the examplepounds of the above formula to the fibrous material to with 0 g/l, 0.5g/l, 1 g/] or 2 g/l of antistatic agent at pH be provided withantistatic protection has proved ap- 5 to 6 for 15 minutes at C, using aliquor ratio of propriate. The fibrous material can be provided with30:1. The material is then centrifuged until the wet pick the antistaticfinish at any desired point in the course of up is per cent, and isdried at C. Because of the its processing, or after it has been finishedin other reabsence of any substantivity, the amount applied to thespects, or even during use. It is also possible, and frefibercorresponds to that calculated.

quently advantageous, to combine the antistatic finish- 35 The hank iswrapped with a strong thread at one end ing operation with otherconventional treatment of the and is cut open at the other end. Afterconditioning, the fibrous material, by treating the fibrous materialwith hank is repeatedly drawn through a brass die of 4.5 mm solutions ofthe compounds of the above formula which diameter until the charge hasreached a maximum, and also contain, for example, softeners, lubricants,brightis then held in a brass half-cylinder of 80 mm diameter eners,smoothing agents or wetting agents. Examples of 40 and 500 mm length,connected to an electrostatic voltsuch known agents are quaternary fattyalkylage meter (Static-voltmeter supplied by Rothschild, ammonium orfatty alkyl-sulfonium compounds, fatty Switzerland). The potential isread off in volts. acid esters, fatty acid alkylamides, tertiary orquater- The hanks are heat-treated in a through-circulation nary fattyacid amide-amines, fatty alkyl sulfates, sulfodryer.

TABLE 1 Product Electrostatic charge of polycaprolactam hanks in voltsat 20C and 65% relative atmospheric humidity Reaction product of Hankbefore heat Hank stored 5 minutes at code exposure 180C treated with g/lof treated with gll of active substance active substance 1 mole ofquaterniz- 1 mole of amine 0 0.5 1.0 0 1.0 2.0 ing agent (untreated)(untreated) Examples A Dimethyl Tris-( Z-hydroxy- +1 ,300 0 0 +1 ,000 0O accordsulfate ethyl)-amine ing to 8 Methyl chloride 0 0 +50 0 o theinvention C 2-Chloroethanol +50 0 0 0 D Benzyl chloride 0 +100 0 Ep-Toluenesulfonic +200 0 +100 0 acid methyl ester F 0.5 mole of 1,4- +500 +50 0 dichlorobutane G .Dimethyl sulfate N-Methyl-bis-(Z-hydroxyethyl)- +50 0 0 0 amine H Methyl chloride +50 0 +100 0 K Dimethylsulfate N-(n-Buty1)-bis- +200 0 +100 0 (2-hydroxyethyl)- amine L Methylchloride +200 0 +200 0 Com- 1 Dimethyl N-Dimethyl-(Z-hyparisulfatedroxyethyU'amine +1,300 +1.100 +1,000 +1.000 +1,100 +1 ,000

TABLE -1 -continued Electrostatic charge of polycaprolactam hanks involts at 20C and 65% relative atmospheric humidity Product Reactionproduct of: Hank before heat Hank stored minutes at code exposure 180Ctreated with g/l of treated'iwith g/l of v active substance activesubstance 1 mole of quatemiz- 1 mole of amine} 0 0.5 L0 0 1.0 2.0 I ingagent (untreated) (untreated) son ll 7 Methyl +1 ,200 +l,000 .+l.100 800exchloride 1 amples lll p-Toluenesulv fonic acid H.300 H.100 +1.000+1,000 methyl ester lV Dimethyl N-Diethyl-(Z-hy- +1 ,200 +1.100 900 700sulfate droxyethyl)-amine V Methyl +1,000 +1.100 +l,l00 900 chloride V1Dimethyl N-Di-n-butyl-(2- sulfate hydroxyethyl)-amine +1.300 +1 ,000+l,100 +1.000 Vll Dimethyl Tris-(2-hydroxyiso- +1.300 +l,100 +1,000 +1,000

sulfate propyl)-amine Vlll Methyl +1,300 +1,300 900 +1.000

chloride lX p-Toluene- +1,400 +l,100 +l,l00 +1.100

sulfonic acid methyl ester TABLE 2 Electrostatic charge of PBS hanks involts at C and 65% relative atmospheric humidity Product Reactionproduct of Hank before heat Hank stored 5 minutes code exposure at 200Ctreated with gll of treated with g/l of active substance activesubstance 1 mole of quaterniz- 1 mole of amine 0 0.5 1.0 0 1.0 2.0 ingagent (untreated) (untreated) Examples A Dimethyl Tris-( 2-hydroxy- +3000 0 -l ,000 0 0 according sulfate ethy1)-amine w to the 8 Methylchloride 0 0 0 0' invention E p-Toluenesul- +50 0 50 0 fonic acid methylester G Dimethyl N-Methyl-bis-(Z- 0 O 0 0 sulfate hydroxyethyl)- amine KDimethyl N-(n-Butyl)-bis- +50 0 100 O sulfate (Z-hydroxyethyl amine Com-1 Dimethyl sulfate N-Dimethyl-(Z- +300 +200 +100 1,000 500 -600 parisonhydroxyethyl)- examples amine ll Methyl chloride +200 +200 800 200 VllDimethyl sulfate Tris-( 2-hydroxy- +200 +200 -700 -600 isopropyl)-amineVlll Methyl chloride +300 +300 -800 300 1X p-Toluene- +350 +200 -1,000800 sulfonic acid methyl ester EXAMPLE 1 A polyamide-6 knitted fabric istreated on a dyebeck using a dilute liquor (liquor ratio :1), with an0.05% strength solution of N-methy1-tri-( 2-hydroxyethyl)- ammoniumchloride at pH 6 and approximately 40C for 10 minutes. Aftercentrifuging to about 30% resid ual moisture content, and drying, thefabric is thermoset at 180 to 200C. A polyamide material treated in thisway does not build up any electrostatic charge during subsequentprocessing, such as lapping and makingup, or during use.

EXAMPLE 2 The surface of a polystyrene molding is sprayed with a 1%strength aqueous solution of N-dimethyl-bis-(Z-hydroxyethyl)-methosulfate which contains 0.05% of sodiumhexylheptylnaphthalenesulfonate to give better wettability. Afterdrying, the molding is antistatic; it

, shows no tendency to build up an electrostatic charge when rubbed andtherefore does not attract dust from the atmosphere.

EXAMPLE 3 3 ,9] 4,496 7 8 material, of at least one ammonium salt of theformula [A9(CH,CH,OH), :l x6

Q Q N(CH CH 'OH) Xe A is alkylene of 2 to 6 carbon atoms and R ishydroxyalkyl of 2 or 3 carbon atoms, alkyl of l to 6 carbon atoms orbenzyl.

2. A fibrous material as set forth in claim I wherein l0 said fibrousmaterials are prepared from polyesters, where X IS. one equivalent of ananion of a water-solu- I polyamides, acrylonitme polymers, polyolefinsor y ble acid, 0 IS hydroxyalkyl of 2 or 3 carbon atoms, alkyl vinylcompounds of l to 6 carbon atoms, benzyl or the radical

1. FIBROUS MATERIAL PROVIDED WITH AN ANTISTATIC FINISH WITH 0.03 TO 2PER CENT BY WEIGHT, BASED ON THE FIBROUS MATERIAL, OF AT LEAST ONEAMMONIUM SALT OF THE FORMULA
 2. A fibrous material as set forth in claim1 wherein said fibrous materials are prepared from polyesters,polyamides, acrylonitrile polymers, polyolefins or polyvinyl compounds.